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# An Evidence Based Model Sign Code - College of Design ...

An Evidence Based Model Sign Code - College of Design ...

## Solution: The distance

Solution: The distance from the center of the sign to the center of the far lane is: • 6 12-6+16=82 ft. The distance from the sign to the point at which the driver needs to be able to read the sign (Visual Reaction Distance) is: • 1.47 45 (7+0.14 10)=555.66 ft Equation 4. For a vertical viewing angle of 5° and a driver eye height of 3.5 ft, Equation 4 can be shorted to that shown in Equation 5. Table 8 summarizes the results of applying this table to a range of letter heights based on a legibility index of 30 ft/in. The line of sign from the vehicle to the sign is: • 82 2 + 555.56 2 = 561.68 ft Using a legibility index of 30 ft/in, the minimum letter height is: • 561.68/30=18.7 inches, use 19 inches. The minimum sign size area is: • 19 2 /144 10 2.5=62.7 ft 2 , use 63 ft 2 Maximum sign height, based on a 5° vertical angle, is: • 0.087 19 30+3.5=53.1 ft, use 53 ft Equation 5. Table 8. Maximum Sign Height Guidelines EXAMPLES FOR USING THE FORMULAS AND TABLES The following presents an example of how to use the information in this document to determine the appropriate minimum letter height, minimum sign size, and maximum sign height given inputs that represent the viewing environment. Given: • An arterial roadway with three lanes in each direction and a 16 ft raised median. • The speed limit on the road is 45 mph. • The center of the sign is assumed to be located 30 ft from the edge of the road. • The sign is in an area with little competition for the driver’s visual attention. • There are 10 letters and no graphics in the sign. Technical Information Related to Electronic Message Displays Electronic Message Displays (EMDs), which are also referred to as electronic message centers or electronic changeable copy signs, are a type of private sector sign that may require special treatment in the development of a model sign ordinance. These signs have unique capabilities to provide a variety of messages in a range of formats. At the low end of the technology scale, these signs use a matrix arrangement to present text and simple graphics. The message or messages may be displayed in a static mode or may scroll or flash. At the high end of the technology scale, these signs are capable of providing television quality types of images. The use of large EMDs is more common for off-premise signing, typically in billboard-type applications. On-premise use of EMDs is more commonly limited to static, scrolling, or alternating messages. The technology for EMDs is far ahead of the research on their impacts and guidelines for use. A 2005 report by the United States Sign Council (Garvey and Pietrucha 2005) indicated that “there has been little research conducted specifically on commercial EMCs.” As such, this Technical Report and model sign code contains relatively little information regarding these types of signs. A Legal and Technical Exploration of On-Premise Sign Regulation: An Evidence Based-Model Sign Code 28